import math
x1, y1, x2, y2=map(float,input().split())
x=abs(x1-x2)
y=abs(y1-y2)
print('{:.5f}'.format(math.sqrt(x*x+y*y))) import math math x1, y1, x2, y2=map(float,input().split()) x1 map(float,input().split()) map float input().split() ().split () input split y1 x2 y2 x=abs(x1-x2) x abs(x1-x2) abs x1-x2 x1 x2 y=abs(y1-y2) y abs(y1-y2) abs y1-y2 y1 y2 print('{:.5f}'.format(math.sqrt(x*x+y*y))) print '{:.5f}'.format(math.sqrt(x*x+y*y)) '{:.5f}'.format '{:.5f}' format math.sqrt(x*x+y*y) math.sqrt math sqrt x*x+y*y x*x x x y*y y y x2, y2=map(float,input().split()) map(float,input().split()) x2 x=abs(x1-x2) abs(x1-x2) x y2=map(float,input().split()) map(float,input().split()) y2 x1, y1, x2, y2=map(float,input().split()) map(float,input().split()) x1 y=abs(y1-y2) abs(y1-y2) y y1, x2, y2=map(float,input().split()) map(float,input().split()) y1
import math
x1, y1, x2, y2=map(float,input().split())
x=abs(x1-x2)
y=abs(y1-y2)
print('{:.5f}'.format(math.sqrt(x*x+y*y)))
